From bc78fc6ed03cfd0ce326e5377a3fabf984f68c38 Mon Sep 17 00:00:00 2001
From: WinterSnowfall <WinterSnowfall@users.noreply.github.com>
Date: Fri, 4 Oct 2024 16:13:35 +0300
Subject: [PATCH] [d3d8] Validate D3D8 present params before conversion

---
 src/d3d8/d3d8_d3d9_util.h | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/d3d8/d3d8_d3d9_util.h b/src/d3d8/d3d8_d3d9_util.h
index ce53699f2..9c9a8c66e 100644
--- a/src/d3d8/d3d8_d3d9_util.h
+++ b/src/d3d8/d3d8_d3d9_util.h
@@ -58,7 +58,12 @@ namespace dxvk {
   }
 
   // (9<-8) D3DD3DPRESENT_PARAMETERS: Returns D3D9's params given an input for D3D8
-  inline d3d9::D3DPRESENT_PARAMETERS ConvertPresentParameters9(const D3DPRESENT_PARAMETERS* pParams) {
+  inline d3d9::D3DPRESENT_PARAMETERS ConvertPresentParameters9(D3DPRESENT_PARAMETERS* pParams) {
+    // A 0 back buffer count needs to be corrected and made visible to the D3D8 application as well
+    pParams->BackBufferCount = std::max(pParams->BackBufferCount, 1u);
+
+    if (pParams->BackBufferFormat == D3DFMT_UNKNOWN)
+      pParams->BackBufferFormat = D3DFMT_X8R8G8B8;
 
     d3d9::D3DPRESENT_PARAMETERS params;
     params.BackBufferWidth = pParams->BackBufferWidth;
@@ -69,7 +74,6 @@ namespace dxvk {
     params.MultiSampleType = d3d9::D3DMULTISAMPLE_TYPE(pParams->MultiSampleType);
     params.MultiSampleQuality = 0; // (D3D8: no MultiSampleQuality), TODO: get a value for this
 
-
     UINT PresentationInterval = pParams->FullScreen_PresentationInterval;
 
     if (pParams->Windowed) {